Purchasing The Licence Keys

To purchase the licence you will need the serial number of your RPi, this can be done from SSH

cat /proc/cpuinfo

Adding The Licence Keys

Add the following to your config.txt

decode_MPG2=0x00000000
decode_WVC1=0x00000000

Replace "00000000" with the licence key that you purchased.

Check If The Keys Are Enabled

If you are having issues with your licence there are some tests you can do to confirm if the licence is enabled or not.

SSH into your Raspberry Pi and run the below commands:

vcgencmd codec_enabled MPG2
vcgencmd codec_enabled WVC1

If MPG2 or WVC1 has been successfully enabled it should return something similar to this:

MPG2=enabled

If it returns disabled you will need to check:

You entered the correct serial number when purchasing the licence.

You have correctly added the licence key to the config.txt file.

You uncommented the relevant lines in the config.txt file by removing the # and space from the start of the line.

You have rebooted before testing.

Device Tree Overlay

Raspberry Pi's latest kernels and firmware now by default use Device Tree (DT) to manage some resource allocation module usage.

The current solution is not a pure Device Tree system -- there is still board support code that creates some platform devices -- but the external interfaces (i2c, i2s, spi) and the audio devices that use them must now be instantiated using a Device Tree Blob (DTB) passed to the kernel by the loader (start.elf).

The main impact of using Device Tree is to change from everything on, relying on module blacklisting to manage contention, to everything off unless requested by the DTB. In order to continue to use external interfaces and the peripherals that attach to them, you will need to add some new settings to your config.txt

Adding Device Tree Overlays

The current supported DTB's can be found in /flash/overlays. These can be set by using any of the following overlays